>>26935814At this point it really isn't known. If you want to use the anime as an example (because really, that's the closest thing to having info on this):
Blue core went to 50% Zygarde with more than 49 Cells.
They show Perfect Zygarde for the Magearna movie but the Blue Core is still captured by Team Flare.
Perfect Zygarde is also shown getting into a fight with either a machine that looks like 50% Zygarde or with a corrupted 50% Zygarde.
In short, no one actually knows.
